hello,
i have not move yet my self but i will be soon as far as i know. At the age of 4 must the child go to shool, at 2 1/2 starts the kindergaten.
check out:
http://onderwijs.amsterdam.nl/live/index.jsp
for all schools in amsterdam
also
http://www.iamsterd.../learning/school_system
i find this good use this:
http://translator.live.com/Default.aspx
by the way in holland the kids go to shool from 9 till 3, but on wesndays until 12.30
hope it helps